The present invention is directed to improved thermally insulated wall constructions, and in particular, an improved wall construction for expanded store front systems.
In the construction of modern day multi-story buildings, a variety of wall systems or curtain wall structures have been utilized. One such system is known as a "stick wall" system and generally is constructed of metal framing members with extruded aluminum members being preferred. The various component parts of a "stick wall" system are factory fabricated with the vertical and horizontal members constructed in predetermined shapes, sizes and lengths and thereafter shipped to the construction site. These members are assembled piece by piece into a grid directly on the building and the grid is then glazed from either the inside or outside of the building depending upon job conditions. Spandrel panels or other types of panels may be installed along with the metal members if desirable.
A typical "stick wall" construction of the type aforenoted is disclosed in U.S. Pat. No. 3,719,014 to Sukolics. The patent discloses a wall construction for mounting panels or the like comprising a vertical support mullion to which there is secured an interior mullion section. The structural portion of the mullion and the interior mullion section interlock through a one way snap lock comprising a nib like portion on the structural portion of the mullion and a channel groove on the interior mullion section. The interior mullion section must be provided with a factory fabricated upper cope having a pair of vertically spaced shoulders and a projection thereon which must be designed specifically to mate with and interlock into the specific horizontal member being used.
The specific design noted above with reference to U.S. Pat. No. 3,719,014 suffers from a number of disadvantages which makes the employment of such a design impractical, energy inefficient and extremely costly. In particular, the design of the vertical mullion is such that the vertical mullion support, which is exposed to exterior environment is in direct contact with the interior mullion section. Thus, the cold member contacts the warm member thus allowing for heat loss through these members as well as forming condensation on these members. Such an arrangement, which allows for heat loss, is highly undesirable in this day of awareness of energy conservation. In addition to the foregoing, a further disadvantage associated with the design of the U.S. Pat. No. 3,719,014 resides in the necessity of making available a plurality of interior mullion sections of different upper cope design in order to accommodate the various horizontal members used depending on whether the construction is to be outside glazed or inside glazed. By requiring a plurality of interior mullion sections, the cost of the construction is increased over that cost which would be incurred if a single mullion section could be used to accommodate both outside glazed and inside glazed horizontal members.
Accordingly, it is a principal object of the present invention to provide a thermally improved expanded store front system wherein a thermal break is provided between the interior and exterior vertical mullion.
It is a particular object of the present invention to provide a thermally improved store front system wherein the vertical mullion section has a single upper cope designed to accommodate various horizontal members.
It is a further object of the present invention to provide an improved store front system which is easily assembled.
It is a still further object of the present invention to provide an expanded store front system which is inexpensive to manufacture.
It is still a further particular object of the present invention to provide an expanded store front system which is architecturally pleasing.
Further objects and advantages of the present invention will be evident from what appears hereinbelow.